A vehicle is known that has a so-called shift-by-wire system that switches a driving range of a vehicle by converting a driver's operation of a shift lever into an electrical signal and by driving, based on the electrical signal, an actuator acting as a shift switching device. Since the shift-by-wire system has no physical (mechanical) relationship of connection between the shift lever and a transmission as seen in the prior art, even when an abnormality incapable of, e.g., switching between forward and reverse movements occurs in the shift-by-wire system, the driver cannot notice the abnormality. Hence, for instance, when an abnormality occurs in the shift-by-wire system upon running at “D” range that is a forward driving range and thereafter an operation of switching to “R” range is made by the driver in accordance with the driver's intention of switching to “R” range that is a reverse driving range, the actual driving range of the transmission may still remain at “D” range (a forward-reverse movement malfunction) even when the shift lever is operated to a position of “R” range. In this case, the driver may consider that switching to “R” range is completed due to the operation of the shift lever to the position of “R” range, as a result of which the vehicle may possibly move forward when the driver steps on an accelerator. This is the reason why the shift-by-wire system includes a means for detecting such an abnormality thereof.
A shift-by-wire control device described in Patent Document 1 for example includes a plurality of shift-by-wire control circuits, a monitoring control means configured to be constituted of another control circuit than the shift-by-wire control circuits, for monitoring the shift-by-wire control circuits, and a permission/prohibition means for individually permitting or prohibiting control executed by the plurality of shift-by-wire control circuits based on a command from the monitoring control means. In a case where an abnormality occurs in one or some of the plurality of shift-by-wire control circuits, the monitoring control means distinguishes an abnormal shift-by-wire control circuit(s) from a normal shift-by-wire control circuit(s) so as to enable detection of an abnormality in the shift-by-wire system. Based on a result of distinguishment of the monitoring control means, the permission/prohibition means permits the continuation of the control for the normal shift-by-wire control circuit(s) and prohibits the control for the abnormal shift-by-wire control circuit(s). In such a case, the monitoring control means imposes an output limitation on the vehicle, e.g., by lowering the engine torque or by applying the brake.